Well force feeding is likely stressing them out quite a bit. How much do they weight? I'd just keep offering every week ONCE a week, and they will eat eventually. Don't try to assist feed unless they are weak and have lost a significant amount of body weight. They can go a REALLY long time without eating. My male just went back on feed after an 8 month fast, so two months isn't really that big of a deal. Keep track of their weights, and if they start to lose a lot of weight I'd suggest a vet visit to rule out internal parasites.